Evap Purge Solenoid Stuck Open

P0446 - EVAP PURGE SOLENOID STUCK OPEN





When Monitored and Set Condition

- When Monitored: Cold start test. Engine Running.
- Set Condition: The Powertrain Control Module (PCM) activates the Evap Purge Solenoid gradually and increases to maximum flow. The PCM monitors the Fuel Tank Pressure Sensor and if the value falls below -40 hPa (0.58 psi) too soon, this DTC is set.





For a complete Powertrain Control Module Circuit Diagram, Schematics and Diagrams.

Diagnostic Test

1. PRE-DIAGNOSTIC CHECK OUT

NOTE: Always perform diagnostics with a fully charged battery.

NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.

NOTE: Check for applicable TSBs related to the problem.

Turn the ignition on.
With the scan tool, read PCM DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Perform this procedure prior to symptom diagnosis.

Continue

- Go To 2

2. CHECK FOR CURRENT DTC
NOTE: If any EVAP/Charcoal Canister DTCs are set, diagnose them first before continuing with P0446.

NOTE: If the PCM detects and stores a DTC, the PCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.

NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.

Turn the ignition on.
With the scan tool, erase PCM DTCs.

NOTE: It maybe necessary to road test the vehicle for this DTC to set.

With the scan tool, read PCM DTCs.
Did this DTC set again?

Yes

- Go To 3

No

- Go To 5

3. CHECK EVAP PURGE SOLENOID FUNCTIONALITY
NOTE: After disconnecting the Evap Purge vacuum connections, inspect the lines and solenoid for any signs of contamination or foreign materials.

With the ignition on.
Using a hand vacuum pump, apply 330 mm Hg (10 in. Hg) to the canister side of the EVAP Purge Solenoid.
Observe the vacuum gauge.
With the scan tool, actuate the PURGE CTRL VALVE.
Does the vacuum drop when the solenoid is actuated?

Yes

- Go To 4

No

- Replace the Evap Purge Solenoid.EVAP Purge Solenoid - Removal.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test

4. EVAP VACUUM SUPPLY HOSE INSPECTION
Turn the ignition off.
Carefully inspect the Evap Purge Solenoid vacuum supply hose for proper routing.
Check for a pinched or plugged vacuum hose to the Purge Solenoid.
Inspect the vacuum port for any damage or restriction.
Were any problems found?

Yes

- Repair the vacuum supply hose/tube as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test

No

- Replace the EVAP Purge Solenoid. EVAP Purge Solenoid - Removal.

5. INTERMITTENT WIRING AND CONNECTORS
The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.

NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.

NOTE: Check for any Technical Service Bulletins that may apply.

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.
Were there any problems found?

Yes

- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test

No

- The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.